merge about pdf HOT 5 OPEN

func appendPDF(newPDFfilename string, filenames []string) {
    merged := pdf.New()

    for _, filename := range filenames {
        file, err := pdf.Load(filename)
        if err != nil {
            log.Fatalln(err)
        }

        merged.Catalog.Pages = append(merged.Catalog.Pages, file.Catalog.Pages...)

        err = file.Close()
        if err != nil {
            log.Fatalln(err)
        }
    }

    err := merged.Save(newPDFfilename)
    if err != nil {
        log.Fatalln(err)
    }
}

$ ./merge -o merge.pdf 34567_1234.pdf Palak_Paneer.pdf 
writing to merge.pdf
panic: %

goroutine 1 [running]:
github.com/nathankerr/pdf.parseObject(0x46f026, 0xd5, 0xd5, 0x0, 0x0, 0x3, 0x0, 0x0)
    /Users/ottob/go/src/github.com/nathankerr/pdf/parse.go:62 +0xd64
github.com/nathankerr/pdf.parseDictionary(0x46f010, 0xeb, 0xeb, 0x0, 0x0, 0x10, 0x0, 0x0)
    /Users/ottob/go/src/github.com/nathankerr/pdf/parse.go:294 +0x8da
github.com/nathankerr/pdf.parseObject(0x46f00e, 0xed, 0xed, 0x0, 0x0, 0xf4, 0x0, 0x0)
    /Users/ottob/go/src/github.com/nathankerr/pdf/parse.go:65 +0x237
github.com/nathankerr/pdf.(*File).parseReferences(0xc820078090, 0xeecf, 0xa, 0x40, 0x0, 0x0)
    /Users/ottob/go/src/github.com/nathankerr/pdf/reference.go:190 +0x1bc8
github.com/nathankerr/pdf.(*File).loadReferences(0xc820078090, 0x0, 0x0)
    /Users/ottob/go/src/github.com/nathankerr/pdf/reference.go:65 +0x748
github.com/nathankerr/pdf.Open(0x7fff5fbffaad, 0xe, 0x2, 0x0, 0x0)
    /Users/ottob/go/src/github.com/nathankerr/pdf/file.go:81 +0x739
main.appendPDF(0x7fff5fbffaa3, 0x9, 0xc82000a120, 0x2, 0x2)
    /Users/ottob/Downloads/merge.go:36 +0x247
main.main()
    /Users/ottob/Downloads/merge.go:23 +0x30d